We have established that large differences in numbers of propionibacteria on the forehead of different subjects are persistent and appear to reflect fundamental differences in the skin. We will determine the relationship of these differences to populations of other kinds of organisms on the same site, and by studies elsewhere on the body, determine whether the differences are systemic. We expect to look for quantitative differences in surface lipids as one element in the cutaneous environment that might correlate with certain surface microbial flora. We will also conduct further evaluations of techniques of harvesting bacteria from skin and evaluations of criteria for identification of ecologically significant differences in populations of Gram positive cocci.